1. Field of the Invention
The present invention relates to a data output encoder that outputs detected positions as data to the outside. More particularly, the invention relates to a data output encoder which, after outputting to an external party internal error information and self-diagnostic information being retained inside, allows its information retaining state to be easily reset by the external party in communication with the data output encoder.
2. Description of the Prior Art
Some prior art data output encoders that output detected positions as data to the outside have an additional feature. This is the ability to retain and output to the outside intra-encoder error information and self-diagnostic information. These kinds of information result illustratively from cases where abnormally high speeds of movement on the scale have exceeded the critical responsive levels of detectors.
The reason for retaining the error information and self-diagnostic information is to make sure that the two kinds of information are delivered unfailingly to the outside even if error signals and other data constituting the information occur only temporarily.
Meanwhile, after the error information and self-diagnostic information are transferred to the external party in communication, it is necessary for the encoder to have its information retaining state reset by the other party. The reset operation is needed to make way for more error information and self-diagnostic information to be obtained anew.
So far, the prior art encoder is reset using one of a few conventional measures: by turning off power to the encoder and then applying power again to execute an information resetting sequence every time power is applied; or by furnishing a dedicated reset line for resetting the information retaining state of the encoder.
These conventional resetting measures have their share of disadvantages. For example, when the encoder is turned off and then powered again for resetting, the startup takes time due to a number of self-diagnostic operations being performed by the encoder concurrently. This amounts to an extra time required to reset the information retaining state of the encoder. Furthermore, furnishing a dedicated reset line for resetting the encoder involves greater power dissipation, more space required for installation and higher costs.